<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<input type="datetime-local" step="01" name="user_date" id="time"/>

<script type="text/javascript" src="js/jquery-1.12.4.min.js"></script>
<script type="text/javascript">
    $(document).on("blur", "#time", function () {
        alert($("#time").val());
    });
</script>
</body>
</html>